JP3141246B2 - Optical information recording / reproducing device - Google Patents
Optical information recording / reproducing deviceInfo
- Publication number
- JP3141246B2 JP3141246B2 JP02402231A JP40223190A JP3141246B2 JP 3141246 B2 JP3141246 B2 JP 3141246B2 JP 02402231 A JP02402231 A JP 02402231A JP 40223190 A JP40223190 A JP 40223190A JP 3141246 B2 JP3141246 B2 JP 3141246B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- light receiving
- information recording
- reproducing apparatus
- optical information
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Optical Recording Or Reproduction (AREA)
- Optical Head (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光ディスク，光磁気デ
ィスクなどの光学的記録媒体を用いて情報の記録，再
生，消去を行う光学的情報記録再生装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical information recording / reproducing apparatus for recording, reproducing, and erasing information using an optical recording medium such as an optical disk and a magneto-optical disk.
【０００２】[0002]
【従来の技術】従来の光学的情報記録再生装置の光ピッ
クアップでは、記録媒体上に約1.6μmの間隔で形成され
る情報トラックに、対物レンズによりレーザ光ビームを
直径約１μmの微小なビームスポットに絞って照射し、
情報の記録，再生，消去を行う。このため、記録媒体と
対物レンズの間隔を１μm程度の精度で約４mmの間隔で
保ちながら、前記情報トラックの略中央に0.1μm程度の
精度でビームスポットを照射させる必要がある。2. Description of the Related Art In an optical pickup of a conventional optical information recording / reproducing apparatus, a laser beam is applied to an information track formed on a recording medium at intervals of about 1.6 μm by a small beam spot having a diameter of about 1 μm by an objective lens. And irradiate
Records, reproduces, and deletes information. For this reason, it is necessary to irradiate a beam spot to the center of the information track with an accuracy of about 0.1 μm while maintaining the distance between the recording medium and the objective lens at an accuracy of about 1 μm at an interval of about 4 mm.
【０００３】また、記録媒体は情報処理速度を向上させ
るために毎分数千回転の高速で回転しており、記録媒体
の面振れや芯振れなどによって情報トラックの位置変化
が高速で発生している。このため、対物レンズを焦点方
向に駆動させるフォーカス制御、およびビームスポット
位置を情報トラックの直交方向に制御するトラッキング
制御を行っている。この制御のためのエラー信号検出に
は、公知のプッシュプル法，臨界角法，非点収差法，ナ
イフエッジ法などが使用され、記録媒体からの反射光を
分割受光素子で受光し、この分割受光素子の分割された
各素子からの出力の差をとった差出力に基づいて前記制
御を行っている。Further, the recording medium rotates at a high speed of several thousand revolutions per minute in order to improve the information processing speed, and a change in the position of the information track occurs at a high speed due to a runout or a center runout of the recording medium. I have. Therefore, focus control for driving the objective lens in the focal direction and tracking control for controlling the beam spot position in the direction perpendicular to the information track are performed. A known push-pull method, a critical angle method, an astigmatism method, a knife edge method, or the like is used for detecting an error signal for this control. Light reflected from a recording medium is received by a divided light receiving element, and the divided light is received. The control is performed based on a difference output obtained by calculating a difference between outputs from the respective divided light receiving elements.
【０００４】上記のエラー信号検出方法は、情報トラッ
クの位置変化に対する検出感度が非常に高く、ビームス
ポットを高速で、かつ高精度に制御できる特徴を有して
いる。The above-described error signal detection method has features that detection sensitivity to a change in the position of an information track is extremely high, and that a beam spot can be controlled at high speed and with high accuracy.
【０００５】[0005]
【発明が解決しようとする課題】上記の従来技術におい
て、エラー信号検出感度が高いために、分割受光素子の
反射光光軸に対する位置調整は厳しい精度を要求されて
おり、検出方法によって数μmの精度が要求され、従来
行われていた分割受光素子を移動させる位置調整では細
かな調整が容易でなく、光ピックアップの量産に対して
大きな障害となっている。In the above-mentioned prior art, since the error signal detection sensitivity is high, the position adjustment of the divided light receiving element with respect to the reflected light optical axis is required to be strictly accurate. Accuracy is required, and fine adjustment is not easy in the conventional position adjustment for moving the divided light receiving elements, which is a major obstacle to mass production of optical pickups.
【０００６】また、分割受光素子上のビームスポットの
位置ずれや強度分布変化を差信号として検出する方法
は、初期の調整誤差によるずれや、記録媒体の反射率や
厚さなどのバラツキによる調整ずれや、周囲環境温度変
化による外的な要因による調整ずれや、経時的な変化に
よる分割受光素子や反射光光軸の移動などの調整ずれか
ら制御誤差が発生することが知られている。[0006] Further, the method of detecting the positional deviation of the beam spot on the divided light receiving element and the change in the intensity distribution as a difference signal involves a deviation due to an initial adjustment error and an adjustment deviation due to variations in the reflectance and thickness of the recording medium. It is known that a control error occurs due to an adjustment deviation due to an external factor due to a change in the ambient environment temperature, or an adjustment deviation due to a change over time such as movement of a divided light receiving element or a reflected light optical axis.
【０００７】そこで、この制御誤差を減ずるために、誤
差を回路やソフトウェアにより定期的に自動補正する機
能を有する情報記録再生装置が一般的になってきてい
る。しかし、従来の自動補正機能は前記差信号の制御誤
差分を電気的にオフセット除去するだけで、本来ずれて
いる分割受光素子と前記反射光光軸の位置を補正するも
のではないため、制御精度劣化や、新たな制御誤差を発
生するなど、自動補正範囲に限界があるという問題を有
していた。Therefore, in order to reduce the control error, an information recording / reproducing apparatus having a function of automatically correcting the error periodically by a circuit or software has become popular. However, the conventional automatic correction function only electrically removes the control error of the difference signal, and does not correct the position of the divided light receiving element and the reflected light optical axis which are originally shifted. There is a problem that the automatic correction range is limited, for example, deterioration or a new control error occurs.
【０００８】従来の補正方法を以下に説明する。調整誤
差がない場合、集光レンズ40で集光された反射光スポッ
ト41の中心と分割受光素子42の分割線位置は図11(a)，
(b)に示すように一致している。この図11(a)の状態の
時、出力されるナイフエッジ法におけるフォーカスエラ
ー信号を図12に示す。A conventional correction method will be described below. When there is no adjustment error, the center of the reflected light spot 41 condensed by the condenser lens 40 and the position of the dividing line of the divided light receiving element 42 are shown in FIGS.
They match as shown in (b). FIG. 12 shows the focus error signal in the knife edge method output in the state of FIG. 11 (a).
【０００９】また、図13(a)，(b)の状態の時、出力され
る前記フォーカスエラー信号を図14に示す。図14は、分
割受光素子42と光軸がずれているため、合焦点で信号に
オフセットが発生し、フォーカスエラー信号(Ｓ字特性)
の極点近傍は、焦点距離の微小変位したときの信号感度
が図12より低い。つまり、単純に前記オフセット除去の
補正を行なっても、信号感度低下は補正できないことは
明らかで、この理由により補正範囲に限界を生じてしま
い、最大に補正してもＳ字特性の極点間(Ｐ−Ｐ)値の範
囲内である。FIG. 14 shows the focus error signal output in the states shown in FIGS. 13 (a) and 13 (b). In FIG. 14, since the optical axis is shifted from the divided light receiving element 42, an offset occurs in the signal at the focal point, and the focus error signal (S-shaped characteristic)
In the vicinity of the pole, the signal sensitivity when the focal length is slightly displaced is lower than that in FIG. In other words, it is clear that the signal sensitivity degradation cannot be corrected even by simply performing the offset removal correction, and for this reason the correction range is limited. (PP) value.
【００１０】本発明の目的は、任意の微少変位量で反射
光光軸と分割受光素子との位置補正が容易かつ確実にで
きる光学的情報記録再生装置を提供することにある。An object of the present invention is to provide an optical information recording / reproducing apparatus capable of easily and reliably correcting the position of a reflected light optical axis and a divided light receiving element with an arbitrary small displacement.
【００１１】[0011]
【課題を解決するための手段】上記の目的を達成するた
め、本発明の第１の手段は、光ビームを対物レンズを介
して記録媒体にビームスポットとして照射し、記録媒体
からの反射光を集光させる集光光路を形成し、前記反射
光を集光光路に設置された分割受光素子の受光面上に集
束光スポットとして入射させ、分割受光素子によって得
られる差出力によって、前記対物レンズのフォーカス制
御とビームスポットのトラッキング制御との少なくとも
一方の制御が行われる光学的情報記録再生装置におい
て、前記集光光路に、前記反射光の光軸に対する挿入角
度を変化させて反射光の光軸を屈折させることによっ
て、前記分割受光素子の素子分割線と交わる方向におい
て受光面上の集束光スポットの位置を移動させる光透過
板を配置したことを特徴とする。In order to achieve the above object, a first means of the present invention is to irradiate a light beam as a beam spot on a recording medium via an objective lens, and to reflect light reflected from the recording medium. A condensing optical path for condensing is formed, and the reflected light is incident as a converging light spot on a light receiving surface of a divided light receiving element provided in the condensing light path. In an optical information recording / reproducing apparatus in which at least one of focus control and beam spot tracking control is performed, the optical axis of the reflected light is changed by changing an insertion angle of the reflected light with respect to the optical axis in the focusing optical path. It is characterized in that a light transmissive plate for moving the position of the focused light spot on the light receiving surface in a direction intersecting with the element dividing line of the divided light receiving element by refraction is provided. To.
【００１２】また、本発明の第２の手段は、光ビームを
対物レンズを介して記録媒体にビームスポットとして照
射し、記録媒体からの反射光を集光させる集光光路を形
成し、前記反射光を集光光路に設置された分割受光素子
の受光面上に集束光スポットとして入射させ、分割受光
素子によって得られる差出力によって、前記対物レンズ
のフォーカス制御とビームスポットのトラッキング制御
との少なくとも一方の制御が行われる光学的情報記録再
生装置において、前記集光光路に屈折率が空気より大き
い光透過板を配置し、この光透過板の前記反射光の光軸
に対する傾斜角度を変化させることによって、前記分割
受光素子の素子分割線と交わる方向において受光面上の
集束光スポットの位置を移動させるように構成したこと
を特徴とする。In a second aspect of the present invention, a light beam is irradiated as a beam spot on a recording medium through an objective lens to form a condensing optical path for condensing light reflected from the recording medium, and At least one of focus control of the objective lens and tracking control of the beam spot is performed by causing light to be incident as a focused light spot on a light receiving surface of a divided light receiving element provided in a condensing optical path, and by a difference output obtained by the divided light receiving element. In the optical information recording / reproducing apparatus in which the control is performed, a light transmission plate having a refractive index larger than air is disposed in the condensing light path, and the inclination angle of the light transmission plate with respect to the optical axis of the reflected light is changed. The position of the focused light spot on the light receiving surface is moved in a direction intersecting the element dividing line of the divided light receiving element.
【００１３】また、本発明の第３の手段は、光ビームを
対物レンズを介して記録媒体にビームスポットとして照
射し、記録媒体からの反射光を集光させる集光光路を形
成し、前記反射光を集光光路に設置された分割受光素子
の受光面上にナイフエッジ板を介して集束光スポットと
して入射させ、分割受光素子によって得られる差出力に
よって、前記対物レンズのフォーカス制御が行われる光
学的情報記録再生装置において、前記集光光路に、屈折
率が空気より大きい光透過板の一部に反射コーティング
を施してなるナイフエッジ板を配置し、このナイフエッ
ジ板の前記光透過板部分における前記反射光の光軸に対
する傾斜角度を変化させることによって、前記分割受光
素子の素子分割線と交わる方向において受光面上の集束
光スポットの位置を移動させるように構成したことを特
徴とする。In a third aspect of the present invention, a light beam is irradiated as a beam spot on a recording medium via an objective lens to form a condensing optical path for condensing light reflected from the recording medium, and An optical system in which light is incident as a converged light spot on a light receiving surface of a divided light receiving element provided on a condensing optical path via a knife edge plate, and focus control of the objective lens is performed by a difference output obtained by the divided light receiving element. In the optical information recording / reproducing apparatus, a knife edge plate in which a reflection coating is applied to a part of a light transmission plate having a refractive index larger than that of air is disposed in the condensing light path, and a knife edge plate in the light transmission plate portion of the knife edge plate is disposed. By changing the inclination angle of the reflected light with respect to the optical axis, the position of the focused light spot on the light receiving surface in the direction intersecting with the element dividing line of the divided light receiving element Characterized by being configured to move to.
【００１４】[0014]
【作用】上記の第１の手段によれば、光透過板によって
反射光の光軸が屈折変化し、分割受光素子の素子分割線
と交わる方向において受光面上の集束光スポットの位置
が光学的に移動し、集束光スポットと分割受光素子との
光学的位置補正がなされる。According to the first means, the optical axis of the reflected light is refracted and changed by the light transmitting plate, and the position of the focused light spot on the light receiving surface is optically changed in the direction intersecting the element dividing line of the divided light receiving element. The optical position of the focused light spot and the divided light receiving elements is corrected.
【００１５】また、第２の手段によれば、屈折率が空気
より大きい光透過板の反射光の光軸に対する傾斜角度を
変化させることにより、反射光の光軸が屈折変化し、分
割受光素子の素子分割線と交わる方向において受光面上
の集束光スポットの位置が光学的に移動し、集束光スポ
ットと分割受光素子との光学的位置補正がなされる。According to the second means, by changing the angle of inclination of the reflected light of the light transmitting plate having a refractive index larger than that of air with respect to the optical axis, the optical axis of the reflected light is refracted and changed. The position of the focused light spot on the light receiving surface is optically moved in the direction intersecting the element dividing line, and the optical position of the focused light spot and the divided light receiving element is corrected.
【００１６】また、第３の手段によれば、屈折率が空気
より大きい光透過板の一部に反射コーティングを施して
なるナイフエッジ板を配置し、このナイフエッジ板の前
記光透過板部分における前記反射光の光軸に対する傾斜
角度を変化させることによって、反射光の光軸が屈折変
化し、フォーカス用の分割受光素子の素子分割線と交わ
る方向において受光面上の集束光スポットの位置が光学
的に移動し、集束光スポットとフォーカス用の分割受光
素子との光学的位置補正がなされる。According to the third means, a knife edge plate in which a reflection coating is applied to a part of a light transmission plate having a refractive index higher than that of air is disposed, and the knife edge plate in the light transmission plate portion of the knife edge plate is disposed. By changing the angle of inclination of the reflected light with respect to the optical axis, the optical axis of the reflected light is refracted and changed, and the position of the focused light spot on the light receiving surface in the direction intersecting with the element dividing line of the divided light receiving element for focusing is optically adjusted. And the optical position of the focused light spot and the focus divided light receiving element is corrected.
【００１７】[0017]
【実施例】以下、本発明の実施例を図面に基づいて説明
する。Embodiments of the present invention will be described below with reference to the drawings.
【００１８】図１は本発明の第１実施例の構成図であ
り、１はレーザダイオード、２はカップリングレンズ、
３はビームスプリッタ、４は対物レンズ、５は記録媒
体、６はビームスプリッタ３の側部に設置された集光レ
ンズ、７はナイフエッジプリズム、８，９は分割受光素
子、10は集光レンズ６とナイフエッジプリズム７との間
に設けられた屈折率が空気より大きい光透過板である。FIG. 1 is a block diagram of a first embodiment of the present invention, wherein 1 is a laser diode, 2 is a coupling lens,
3 is a beam splitter, 4 is an objective lens, 5 is a recording medium, 6 is a condensing lens provided on the side of the beam splitter 3, 7 is a knife edge prism, 8, 9 are divided light receiving elements, and 10 is a condensing lens. This is a light transmitting plate provided between the knife edge prism 6 and the knife edge prism 7 and having a refractive index larger than that of air.
【００１９】同図において、レーザダイオード１から出
射した光ビームＡは、カップリングレンズ２，ビームス
プリッタ３，対物レンズ４を通り、記録媒体５上にビー
ムスポットＳとして集光する。前記記録媒体５で反射さ
れた反射光Ｂは、再び対物レンズ４を通り、ビームスプ
リッタ３で全光量または一部の光量が検出系の分割受光
素子８，９方向へ反射される。この検出系では反射光Ｂ
は、集光レンズ６により分割受光素子８，９へ集光させ
られ、かつ光透過体10を通り、フォ−カス制御のエラ−
信号検出用の分割受光素子８の前でナイフエッジプリズ
ム７で一部が光遮断されて入射し、またトラッキング制
御のエラ−信号検出用の分割受光素子９にはナイフエッ
ジプリズム７で反射されて入射する。In FIG. 1, a light beam A emitted from a laser diode 1 passes through a coupling lens 2, a beam splitter 3, and an objective lens 4, and is focused on a recording medium 5 as a beam spot S. The reflected light B reflected by the recording medium 5 passes through the objective lens 4 again, and the entire or partial light amount is reflected by the beam splitter 3 toward the divided light receiving elements 8 and 9 of the detection system. In this detection system, reflected light B
Are focused on the divided light receiving elements 8 and 9 by the condenser lens 6 and pass through the light transmitting body 10 to be focused control errors.
A part of the light is cut off by the knife edge prism 7 in front of the divided light receiving element 8 for signal detection, and the light is incident. The divided light receiving element 9 for detecting an error signal for tracking control is reflected by the knife edge prism 7. Incident.
【００２０】図２は分割受光素子９の受光面を示す説明
図であり、二分割された分割受光素子９の分割線11上に
反射光Ｂの集束光スポット12が位置し、トラッキングエ
ラ−信号の検出は、公知のように分割線11に対する集束
光スポット12の強度分布変化を二分割された分割受光素
子９において、出力差として検出することによって行わ
れる。この図２では、分割受光素子９を図示したが、分
割受光素子８も同様に分割線11に対する集束光スポット
12の位置ずれによる差出力からフォーカスエラー信号が
検出される。FIG. 2 is an explanatory view showing the light receiving surface of the divided light receiving element 9. The focused light spot 12 of the reflected light B is located on the dividing line 11 of the divided light receiving element 9 and the tracking error signal. Is detected by detecting a change in the intensity distribution of the focused light spot 12 with respect to the dividing line 11 as an output difference in the divided two light receiving elements 9 as is well known. In FIG. 2, the divided light receiving element 9 is illustrated, but the divided light receiving element 8 is also focused light spot with respect to the dividing line 11.
A focus error signal is detected from the difference output due to the 12 position shifts.
【００２１】図２において、上記のエラー信号検出のた
め、前記分割受光素子８，９の分割線11の位置は、反射
光Ｂの集束光スポット12に対して正確に補正する必要が
あり、第１実施例では上記の補正のため光透過板10を用
いている。In FIG. 2, the position of the dividing line 11 of the divided light receiving elements 8 and 9 needs to be accurately corrected with respect to the focused light spot 12 of the reflected light B in order to detect the above error signal. In one embodiment, the light transmitting plate 10 is used for the above correction.
【００２２】すなわち、図３に示すように、屈折率の違
う二つの物質の境界を光が進行する時、スネルの法則に
従って屈折することは周知であって、このスネルの法則
によれば、屈折率ｎ1，ｎ2の二つの物質の境界面に対す
る光の入射角θ1と出射角θ2との間には、That is, as shown in FIG. 3, it is well known that when light travels along the boundary between two materials having different refractive indices, it refracts according to Snell's law. Between the incident angle θ 1 and the outgoing angle θ 2 of the light with respect to the interface between the two substances having the ratios n 1 and n 2 ,
【００２３】[0023]
【数１】 sinθ2／sinθ1＝ｎ1／ｎ2 ## EQU1 ## sin θ 2 / sin θ 1 = n 1 / n 2
【００２４】の関係式が成り立つ。The following relational expression holds.
【００２５】上記の法則を利用し、図４(a),（b)に示す
説明図のように、屈折率が１より大きい屈折率ｎの光透
過板10を反射光Ｂに挿入すると、屈折の現象により反射
光Ｂの進路が光透過板10の挿入する角度により変化す
る。この反射光Ｂの進路の変化量は、挿入される光透過
板10の屈折率，断面形状，挿入角度によって定まる。本
実施例では反射光Ｂ中に平行平板の断面形状をもつ光透
過板10の挿入例を示している。反射光Bの光軸Lに対して
垂直に前記光透過板10を挿入した図４(a)の場合は、光
軸Ｌの進路の変化は発生せず、光軸Ｌに対して角度θ傾
けて光透過板10を挿入した図４(b)の場合は光軸Ｌの進
路に変化を発生する。この進路の変化は光透過板10の断
面形状により平行移動となり、その変化移動量Δは図５
のように屈折率ｎと角度θにより決定される値κと光透
過板10の板厚ｔとの間で下記の数２の関係が成り立つ。Using the above rule, as shown in FIGS. 4A and 4B, when a light transmitting plate 10 having a refractive index n greater than 1 is inserted into the reflected light B, the refractive Due to the above phenomenon, the path of the reflected light B changes depending on the angle at which the light transmitting plate 10 is inserted. The amount of change in the path of the reflected light B is determined by the refractive index, cross-sectional shape, and insertion angle of the light transmitting plate 10 to be inserted. This embodiment shows an example in which the light transmitting plate 10 having a parallel-plate cross section is inserted into the reflected light B. In the case of FIG. 4A in which the light transmitting plate 10 is inserted perpendicularly to the optical axis L of the reflected light B, the path of the optical axis L does not change and the optical axis L is inclined at an angle θ with respect to the optical axis L. 4B in which the light transmitting plate 10 is inserted, a change occurs in the course of the optical axis L. This change in the course is parallel movement due to the cross-sectional shape of the light transmitting plate 10, and the amount of change Δ is shown in FIG.
The following equation 2 holds between the value κ determined by the refractive index n and the angle θ and the plate thickness t of the light transmitting plate 10.
【００２６】[0026]
【数２】 Δ＝ｔ・κ[Expression 2] Δ = t · κ
【００２７】上記の数２と図５により、反射光Ｂの光軸
Ｌの変化移動量Δと光透過板10の挿入角度θの関係は、
光透過板10の板厚ｔおよび屈折率ｎを適宜に選ぶことに
より自由に設定できる。このことは、光透過板10の挿入
角度θを調整して分割受光素子８，９上の集束光スポッ
ト12を目的の位置精度に補正させようとした場合、挿入
角度θの調整精度，固定精度から求めた板厚ｔ，屈折率
ｎを設定することにより容易に目的の集束光スポット12
の位置精度を得ることを可能とする。From the above equation (2) and FIG. 5, the relationship between the change moving amount Δ of the optical axis L of the reflected light B and the insertion angle θ of the light transmitting plate 10 is as follows.
The thickness t and the refractive index n of the light transmitting plate 10 can be freely set by appropriately selecting them. This means that when the insertion angle θ of the light transmitting plate 10 is adjusted to correct the focused light spot 12 on the divided light receiving elements 8 and 9 to the target position accuracy, the adjustment accuracy of the insertion angle θ and the fixed accuracy The target focused light spot 12 can be easily set by setting the plate thickness t and the refractive index n obtained from
Position accuracy can be obtained.
【００２８】また、図６に示す本発明の第２実施例のよ
うに複数枚の透過板10，20を配置することで、粗調，微
調を組合せて行い、補正範囲および補正精度を自由に設
定することも可能である。Further, by arranging a plurality of transmission plates 10 and 20 as in the second embodiment of the present invention shown in FIG. 6, coarse adjustment and fine adjustment are performed in combination, and the correction range and the correction accuracy can be freely adjusted. It is also possible to set.
【００２９】図７は図６を基本にした調整機構の一例を
示す構成図であり、集光レンズ６と分割受光素子９，８
との間に、厚みの異なる２枚の光透過板21，22を配置
し、各光透過板21，22回転可能に支持して、反射光Ｂの
光軸に対する傾斜角度を各光透過板21，22に連結された
サーボモータ23，24のアームロッド25，26の移動によっ
て変化させることができるようにしてある。FIG. 7 is a structural view showing an example of an adjusting mechanism based on FIG. 6, and includes a condenser lens 6 and divided light receiving elements 9 and 8.
And two light transmitting plates 21 and 22 having different thicknesses are disposed between the light transmitting plates 21 and 22 and rotatably supported by the respective light transmitting plates 21 and 22 so that the inclination angle of the reflected light B with respect to the optical axis is set to each light transmitting plate 21. , 22 can be changed by movement of arm rods 25, 26 of servo motors 23, 24 connected to the motor.
【００３０】前記厚みの大きい光透過板21は分割受光素
子８，９上の反射光Ｂの集束光スポット12を大きく変化
させるものであり、また厚みの小さい光透過板22は前記
集束光スポット12を微少変位させるためのものである。The thick light transmitting plate 21 changes the focused light spot 12 of the reflected light B on the divided light receiving elements 8 and 9 largely, and the thin light transmitting plate 22 changes the focused light spot 12. Is to be slightly displaced.
【００３１】上記の第２実施例は、従来の電気的なオフ
セット除去補正ではなく、光軸の調整を行なうため、図
14の信号を元の図12の信号に補正することが可能にな
り、自動補正範囲を広げることができる。In the second embodiment, the optical axis is adjusted instead of the conventional electric offset removal correction.
The signal of 14 can be corrected to the original signal of FIG. 12, and the automatic correction range can be expanded.
【００３２】また、第２実施例では２枚の光透過板21，
22を配置した構成を示したが、光透過板の枚数は１枚、
あるいは３枚以上でもよい。In the second embodiment, two light transmitting plates 21 and
Although the configuration in which 22 are arranged is shown, the number of light transmitting plates is one,
Alternatively, three or more sheets may be used.
【００３３】また、前記光透過板21，22の挿入角度(傾
斜角度)θは、連続的に変化させずとも、段階的に変化
させて調整誤差を段階的に補正してもよく、その段階間
の補正できない部分の補正は、従来の電気的オフセット
除去の補正方法を併用することで、十分な補正範囲及び
補正精度を確保できる。The insertion angle (tilt angle) θ of the light transmitting plates 21 and 22 may not be changed continuously, but may be changed stepwise to correct the adjustment error stepwise. For a portion that cannot be corrected during the period, a sufficient correction range and correction accuracy can be secured by using a conventional correction method for removing electric offset.
【００３４】尚、上述の説明ではフォーカス信号につい
て説明しているが、補正する信号はフォーカス信号に限
定するものではない。また補正量を検知する手段は、従
来より公知の各種方式があり、本実施例では補正量検知
手段自体を特に限定しない。In the above description, the focus signal is described, but the signal to be corrected is not limited to the focus signal. Means for detecting the correction amount is conventionally known in various types, and the present embodiment does not particularly limit the correction amount detection means.
【００３５】図８は本発明の第３実施例の構成図、図９
は第３実施例の要部の説明図であり、基本的構成は図１
と同様であって、図１で説明した部材に対応する部材に
は同一符号を付して、詳しい説明は省略した。この第３
実施例は、集光レンズ６と分割受光素子８，９との間
に、透明板30の一部に反射コーティング31を施したナイ
フエッジ板32を配置しており、このナイフエッジ板32
は、反射コーティング31でエッジ部33を形成して、従来
のナイフエッジプリズムの機能を有し、記録媒体５から
の反射光Ｂの一部をトラッキング制御用の分割受光素子
９へ反射させ、透明板30の反射コーティング31が施され
ていない部分30ａを通過した反射光Ｂがフォーカス制御
用の分割受光素子８へ向うようにした構成である。FIG. 8 is a block diagram of a third embodiment of the present invention, and FIG.
FIG. 4 is an explanatory view of a main part of the third embodiment, and the basic configuration is shown in FIG.
The same reference numerals are given to members corresponding to the members described in FIG. 1, and detailed description is omitted. This third
In this embodiment, a knife edge plate 32 in which a transparent plate 30 is provided with a reflection coating 31 is disposed between the condenser lens 6 and the divided light receiving elements 8 and 9.
Has a function of a conventional knife-edge prism by forming an edge portion 33 with a reflective coating 31 to reflect a part of the reflected light B from the recording medium 5 to a divided light receiving element 9 for tracking control, and The configuration is such that reflected light B passing through a portion 30a of the plate 30 where the reflective coating 31 is not applied is directed to the divided light receiving element 8 for focus control.
【００３６】上記の第３実施例では、前記ナイフエッジ
板32の反射光Ｂの光軸に対する取付け角度を調整するこ
とにより、フォーカス用の分割受光素子８上の集束光ス
ポットの位置補正を行うことができる。この位置補正の
ためにナイフエッジ板32の角度を変化させた場合、トラ
ッキング用の分割受光素子９へ反射する反射光Ｂは、ト
ラッキング用の分割受光素子９の分割線方向に移動する
だけで分割線を超える光量がないので、トラッキング信
号には何等の影響も及ぼさない。またトラッキング用の
分割受光素子９は、受光面の集束光スポットが調整によ
り移動しても集束光スポットが受光面を外れないだけの
十分な面積であり、かつ角度調整により反射光量が変動
しないように、角度調整のための回転中心の軸線位置を
考慮しなくてはならない。In the third embodiment, the position of the focused light spot on the divided light-receiving element 8 for focusing is corrected by adjusting the mounting angle of the knife edge plate 32 with respect to the optical axis of the reflected light B. Can be. When the angle of the knife edge plate 32 is changed for the position correction, the reflected light B reflected to the divided light receiving element 9 for tracking is divided only by moving in the direction of the dividing line of the divided light receiving element 9 for tracking. Since there is no light quantity exceeding the line, the tracking signal has no influence. The divided light receiving element 9 for tracking has a sufficient area so that the focused light spot on the light receiving surface does not deviate from the light receiving surface even if the focused light spot moves by adjustment, and the reflected light amount does not fluctuate due to the angle adjustment. In addition, the position of the axis of the rotation center for adjusting the angle must be considered.
【００３７】第３実施例では、図９に示すように、エッ
ジライン34と角度調整用の回転軸中心35とが同一軸心に
なるように構成してある。In the third embodiment, as shown in FIG. 9, the edge line 34 and the rotation axis center 35 for angle adjustment are configured to have the same axis.
【００３８】上述のように本実施例では、光ピックアッ
プの調整作業を簡便化するとともに作業時間を短縮で
き、量産性を向上させることができる。また、従来の分
割受光素子を面内移動させる調整に代えて光透過板ある
いはナイフエッジ板の角度調整を行うため、従来ではＸ
Ｙステージなどの特殊治具が必要であったが本実施例で
は調整ドライバなどの簡易治工具で行え、一軸回転の調
整であるため自動化も容易である。また上記の従来の調
整方法より調整感度が低いため調整が容易になる。As described above, in the present embodiment, the operation of adjusting the optical pickup can be simplified, the operation time can be shortened, and the mass productivity can be improved. In addition, since the angle adjustment of the light transmitting plate or the knife edge plate is performed instead of the conventional adjustment for moving the divided light receiving element in the plane, the conventional X
Although a special jig such as a Y stage was required, in the present embodiment, it can be performed with a simple jig such as an adjustment driver, and since it is a one-axis rotation adjustment, automation is easy. Further, since the adjustment sensitivity is lower than that of the above-described conventional adjustment method, the adjustment is facilitated.
【００３９】尚、本実施例では集束光である反射光Ｂや
平行平板の光透過板10，20，21，22を用いているが、平
行光の反射光Ｂ部分に光透過板10，20，21，22を備えて
もよく、また光透過板10，20，21，22とナイフエッジ板
32の構造としては前記屈折現象を応用して光路に変化を
与えうるものであれば使用できる。In this embodiment, the reflected light B which is a convergent light and the parallel plate light transmitting plates 10, 20, 21, and 22 are used. , 21, 22 and the light transmitting plates 10, 20, 21, 22 and the knife edge plate
As the structure 32, any structure can be used as long as it can change the optical path by applying the refraction phenomenon.
【００４０】また、上述した光透過板による補正機能を
各分割受光素子８，９に対して独立して作用させるた
め、図10に示すように分割受光素子８，９前の各反射光
Ｃ，Ｄに前記光透過板10(20，21，22)を配置することも
考えられる。Further, since the above-described correction function by the light transmitting plate is applied independently to each of the divided light receiving elements 8 and 9, as shown in FIG. It is also conceivable to arrange the light transmitting plate 10 (20, 21, 22) in D.
【００４１】また、前記光透過板10，20，21，22とナイ
フエッジ板32に対し上記の調整を行った後、ねじ固定，
接着固定することで、衝撃や経時変化による光透過板1
0，20，21，22とナイフエッジ板32の調整ずれを防止で
きる。After the above-mentioned adjustments are made to the light transmitting plates 10, 20, 21, 22 and the knife edge plate 32, the screws are fixed.
Light transmission plate 1
The misalignment between 0, 20, 21, 22 and the knife edge plate 32 can be prevented.
【００４２】また前記光透過板10，20，21，22とナイフ
エッジ板32の透過面に反射防止用のコーティングを施す
ことで、記録媒体５からの反射光Ｂの反射損失を抑制で
きる。By applying an anti-reflection coating to the transmission surfaces of the light transmission plates 10, 20, 21, 22 and the knife edge plate 32, the reflection loss of the reflected light B from the recording medium 5 can be suppressed.
【００４３】[0043]
【発明の効果】以上説明したように、本発明の各手段に
よれば、反射光の集光光路に設置された光透過板によっ
て、反射光の光軸を屈折させることにより、分割受光素
子の素子分割線と交わる方向において受光面上の集束光
スポットの位置を任意の微小変化量で調整でき、容易か
つ確実に集束光スポットと分割受光素子との光学的位置
補正が行える光学的情報記録再生装置を提供できる。As described above, according to each means of the present invention, the optical axis of the reflected light is refracted by the light transmitting plate provided in the condensing light path of the reflected light, so that the divided light receiving element is provided. Optical information recording / reproducing that can adjust the position of the focused light spot on the light receiving surface in the direction intersecting the element dividing line with an arbitrary minute change amount, and can easily and surely correct the optical position of the focused light spot and the divided light receiving element Equipment can be provided.
【図１】本発明の光学的情報記録再生装置の第１実施例
の構成図である。FIG. 1 is a configuration diagram of a first embodiment of an optical information recording / reproducing apparatus of the present invention.
【図２】分割受光素子の受光面を示す説明図である。FIG. 2 is an explanatory diagram showing a light receiving surface of a divided light receiving element.
【図３】光の屈折状態の説明図である。FIG. 3 is an explanatory diagram of a refraction state of light.
【図４】光透過板の作用を示す説明図である。FIG. 4 is an explanatory view showing an operation of a light transmitting plate.
【図５】光透過板の特性図である。FIG. 5 is a characteristic diagram of the light transmitting plate.
【図６】本発明の第２実施例の要部の構成図である。FIG. 6 is a configuration diagram of a main part of a second embodiment of the present invention.
【図７】図６の光透過板の調整機構を示す構成図であ
る。FIG. 7 is a configuration diagram illustrating an adjustment mechanism of the light transmitting plate of FIG. 6;
【図８】本発明の第３実施例の構成図である。FIG. 8 is a configuration diagram of a third embodiment of the present invention.
【図９】図８の第３実施例の要部の説明図である。FIG. 9 is an explanatory diagram of a main part of the third embodiment of FIG. 8;
【図１０】光透過板の他の配置列を示す構成図である。FIG. 10 is a configuration diagram showing another arrangement row of the light transmitting plate.
【図１１】調整誤差がない場合の分割受光素子の受光状
態を示す説明図である。FIG. 11 is an explanatory diagram showing a light receiving state of a divided light receiving element when there is no adjustment error.
【図１２】図11の場合のナイフエッジ法によるフォーカ
スエラー信号の波形図である。FIG. 12 is a waveform diagram of a focus error signal by the knife edge method in the case of FIG. 11;
【図１３】調整誤差がある場合の分割受光素子の受光状
態を示す説明図である。FIG. 13 is an explanatory diagram showing a light receiving state of the divided light receiving elements when there is an adjustment error.
【図１４】図13の場合のナイフエッジ法によるフォーカ
スエラー信号の波形図である。14 is a waveform diagram of a focus error signal by the knife edge method in the case of FIG.
１…レーザダイオード、 ４…対物レンズ、 ５…記録
媒体、 ８，９…分割受光素子、 10，20，21，22…光
透過板、 32…ナイフエッジ板、 Ａ…光ビーム、Ｂ，
Ｃ，Ｄ…反射光、 Ｓ…ビームスポット。DESCRIPTION OF SYMBOLS 1 ... Laser diode, 4 ... Objective lens, 5 ... Recording medium, 8, 9 ... Split light receiving element, 10, 20, 21, 22 ... Light transmission plate, 32 ... Knife edge plate, A ... Light beam, B,
C, D: reflected light, S: beam spot.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平２−149933（ＪＰ，Ａ) 特開 平２−79225（ＪＰ，Ａ) 特開 平１−298526（ＪＰ，Ａ) 特開 平１−282746（ＪＰ，Ａ) 特開 昭57−181504（ＪＰ，Ａ) 特開 昭61−248241（ＪＰ，Ａ) 特開 昭58−60436（ＪＰ，Ａ) 特開 平１−91327（ＪＰ，Ａ) 実開 平２−72416（ＪＰ，Ｕ) 実開 昭63−157817（ＪＰ，Ｕ) ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-149933 (JP, A) JP-A-2-79225 (JP, A) JP-A-1-298526 (JP, A) JP-A-1-298526 282746 (JP, A) JP-A-57-181504 (JP, A) JP-A-61-248241 (JP, A) JP-A-58-60436 (JP, A) JP-A-1-91327 (JP, A) Japanese Utility Model Hei 2-72416 (JP, U) Japanese Utility Model Showa 63-157817 (JP, U)
Claims (10)
にビームスポットとして照射し、記録媒体からの反射光
を集光させる集光光路を形成し、前記反射光を集光光路
に設置された分割受光素子の受光面上に集束光スポット
として入射させ、分割受光素子によって得られる差出力
によって、前記対物レンズのフォーカス制御とビームス
ポットのトラッキング制御との少なくとも一方の制御が
行われる光学的情報記録再生装置において、前記集光光
路に、前記反射光の光軸に対する挿入角度を変化させて
反射光の光軸を屈折させることによって、前記分割受光
素子の素子分割線と交わる方向において受光面上の集束
光スポットの位置を移動させる光透過板を配置したこと
を特徴とする光学的情報記録再生装置。1. A light beam is irradiated to a recording medium as a beam spot through an objective lens to form a condensing optical path for condensing light reflected from the recording medium, and the reflected light is provided in the condensing optical path. Optical information recording in which a focused light spot is made incident on the light receiving surface of the divided light receiving element and at least one of focus control and beam spot tracking control of the objective lens is performed by a difference output obtained by the divided light receiving element. In the reproducing apparatus, by changing the insertion angle of the reflected light with respect to the optical axis and refracting the optical axis of the reflected light in the condensing light path, the light receiving surface on the light receiving surface in the direction intersecting with the element dividing line of the divided light receiving element An optical information recording / reproducing apparatus, comprising a light transmitting plate for moving a position of a focused light spot.
にビームスポットとして照射し、記録媒体からの反射光
を集光させる集光光路を形成し、前記反射光を集光光路
に設置された分割受光素子の受光面上に集束光スポット
として入射させ、分割受光素子によって得られる差出力
によって、前記対物レンズのフォーカス制御とビームス
ポットのトラッキング制御との少なくとも一方の制御が
行われる光学的情報記録再生装置において、前記集光光
路に屈折率が空気より大きい光透過板を配置し、この光
透過板の前記反射光の光軸に対する傾斜角度を変化させ
ることによって、前記分割受光素子の素子分割線と交わ
る方向において受光面上の集束光スポットの位置を移動
させるように構成したことを特徴とする光学的情報記録
再生装置。2. A condensing optical path for irradiating a recording medium with a light beam as a beam spot via an objective lens to form a condensing light path for condensing reflected light from the recording medium, and setting the reflected light on the condensing light path. Optical information recording in which a focused light spot is made incident on the light receiving surface of the divided light receiving element and at least one of focus control and beam spot tracking control of the objective lens is performed by a difference output obtained by the divided light receiving element. In the reproducing apparatus, a light transmitting plate having a refractive index larger than air is disposed in the condensing light path, and an inclination angle of the light transmitting plate with respect to an optical axis of the reflected light is changed, so that an element dividing line of the divided light receiving element is formed. An optical information recording / reproducing apparatus configured to move a position of a focused light spot on a light receiving surface in a direction intersecting with the optical information recording / reproducing apparatus.
とする請求項１又は２記載の光学的情報記録再生装置。3. The optical information recording / reproducing apparatus according to claim 1, wherein a plurality of said light transmitting plates are provided.
対する入射位置の補正後に固定することを特徴とする請
求項１又は２記載の光学的情報記録再生装置。4. The optical information recording / reproducing apparatus according to claim 1, wherein the light transmitting plate is fixed after correcting an incident position of the reflected light with respect to the divided light receiving element.
ィングを施したことを特徴とする請求項１又は２記載の
光学的情報記録再生装置。5. The optical information recording / reproducing apparatus according to claim 1, wherein an anti-reflection coating is applied to a transmission surface of the light transmission plate.
にビームスポットとして照射し、記録媒体からの反射光
を集光させる集光光路を形成し、前記反射光を集光光路
に設置された分割受光素子の受光面上にナイフエッジ板
を介して集束光スポットとして入射させ、分割受光素子
によって得られる差出力によって、前記対物レンズのフ
ォーカス制御が行われる光学的情報記録再生装置におい
て、前記集光光路は、屈折率が空気より大きい光透過板
の一部に反射コーティングを施してなるナイフエッジ板
を配置し、このナイフエッジ板の前記光透過板部分にお
ける前記反射光の光軸に対する傾斜角度を変化させるこ
とによって、前記分割受光素子の素子分割線と交わる方
向において受光面上の集束光スポットの位置を移動させ
るように構成したことを特徴とする光学的情報記録再生
装置。6. A light beam is irradiated as a beam spot on a recording medium via an objective lens to form a converging light path for condensing reflected light from the recording medium, and the reflected light is set in the condensing light path. An optical information recording / reproducing apparatus in which a focused light spot is incident on a light receiving surface of a divided light receiving element via a knife edge plate as a focus and the focus of the objective lens is controlled by a difference output obtained by the divided light receiving element. The light path includes a knife-edge plate having a reflective coating applied to a part of a light-transmitting plate having a refractive index larger than that of air, and an inclination angle of the knife-edge plate with respect to an optical axis of the reflected light at the light-transmitting plate portion. By changing the position of the focused light spot on the light receiving surface in the direction intersecting the element dividing line of the divided light receiving element. An optical information recording / reproducing apparatus characterized by the following.
ーティングの境界によって形成したことを特徴とする請
求項６記載の光学的情報記録再生装置。7. The optical information recording / reproducing apparatus according to claim 6, wherein an edge portion of said knife edge plate is formed by a boundary of a reflection coating.
素子に対する入射位置の補正後に固定することを特徴と
する請求項６記載の光学的情報記録再生装置。8. The optical information recording / reproducing apparatus according to claim 6, wherein the knife edge plate is fixed after correcting the incident position of the reflected light to the divided light receiving element.
も一部に反射防止コーティングを施したことを特徴とす
る請求項６記載の光学的情報記録再生装置。9. The optical information recording / reproducing apparatus according to claim 6, wherein an anti-reflection coating is applied to at least a part of the transmission surface of the knife edge plate.
角度調整のための回転中心とが同一軸心となるように構
成したことを特徴とする請求項６記載の光学的情報記録
再生装置。10. The optical information recording / reproducing apparatus according to claim 6, wherein an edge line of said knife edge plate and a rotation center for adjusting an angle are coaxial.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02402231A JP3141246B2 (en) | 1990-04-10 | 1990-12-14 | Optical information recording / reproducing device |
Applications Claiming Priority (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9313890 | 1990-04-10 | ||
| JP4883790 | 1990-05-10 | ||
| JP2-209140 | 1990-08-09 | ||
| JP20914090 | 1990-08-09 | ||
| JP2-93138 | 1990-08-09 | ||
| JP2-48837 | 1990-08-09 | ||
| JP02402231A JP3141246B2 (en) | 1990-04-10 | 1990-12-14 | Optical information recording / reproducing device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03292637A JPH03292637A (en) | 1991-12-24 |
| JP3141246B2 true JP3141246B2 (en) | 2001-03-05 |
Family
ID=27462270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02402231A Expired - Fee Related JP3141246B2 (en) | 1990-04-10 | 1990-12-14 | Optical information recording / reproducing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3141246B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0714175A (en) * | 1993-06-25 | 1995-01-17 | Nec Corp | Focusing error detecting device |
-
1990
- 1990-12-14 JP JP02402231A patent/JP3141246B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03292637A (en) | 1991-12-24 |
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